They followed that hit with "Captain America: Civil War" which topped the international box office in 2016.

Since then the Russos have been working on their next two films for the Marvel juggernaut, the first of which, "Avengers: Infinity War" is expected to become one of the highest grossing films of all time.

"Avengers: Infinity War" [courtesy: Marvel Studios]

It's a huge undertaking for Cleveland's native sons, as the film not only includes superheroes like Captain America, Iron Man and the rest of the Avengers, it also incorporates Dr. Strange, the Guardians of the Galaxy and many of the characters from Black Panther.

The scope of "Infinity War" and its sequel makes them the brothers' most ambitious and challenging project to date, and that's what they love about them.

"Joe and I love to find creative challenges for ourselves that push us into areas we haven't necessarily explored before and certainly dealing with an ensemble of this size is something we've never dealt with before and something we've really enjoyed creatively," Anthony Russo said.

With so many A-list stars like Chris Pratt, Robert Downey Jr., Scarlett Johansson and Chadwick Boseman, the Russos have created a family atmosphere based on mutual respect as they understand how complex these two films are to produce.

"So everyone knows they're there to help facilitate a process that's bigger than them. That's how they approach the job. I think it's born of the idea that we're all very happy with this work. We're all very excited by it creatively," Anthony said.

Ever since 2008's "Iron Man," the Marvel Cinematic Universe has grown exponentially, releasing two or three superhero films per year. Critics say Hollywood is pandering to these comic book characters and not allowing room for different voices.

Joe Russo sees their point but says there's more to it.

"I do think that you can tell a very humanistic story within this genre and tell really elevated stories that reach a lot of people because a lot of people have an emotional connection to the material. So I think instead of denigrating the genre, look for ways to expand it and innovate it," he said.

Anthony Russo and Robert Downey Jr. on the set of "Avengers: Infinity War" [courtesy: Marvel Studios]

Meanwhile Anthony says making a conscious choice to comment on contemporary society with these movies gives them a weight comparable to classic films.

"Working with a character called 'Captain America,' Joe and I felt responsible to really think about what that means in the world today and what do we want to say about America and the world today. I think those movies are laced with a lot of big ideas in terms of where those questions can lead us," he said.

Chris Evans in "Avengers: Infinity War" [courtesy: Marvel Studios]

"Avengers: Infinity War" opens nationwide this weekend, while its unnamed sequel (also directed by the Russo brothers) comes out in May of next year.

What do you think about the Marvel Cinematic Universe? Is it all hype? Or is there more to it than just comic-book characters battling on screen? Let us know your thoughts on our Sound of Applause Facebook page.